Flurry of News Articles - Milky Way Predicted To Have Many Earth-Sized Planets.

10.29.2010

Milky Way Predicted To Have Many Earth-Sized Planets. The Washington Post (10/29, A3, Kaufman, 605K) reports, “Nobody has seen them yet, but scientists now believe there are tens of billions of planets the general size and bulk of Earth in the Milky Way galaxy alone - a startling conclusion based on four years of viewing a small section of the nighttime sky.” Andrew Howard and Geoffrey Marcy of UC Berkeley estimate that a quarter of the galaxy’s stars have similar sized planets. “Their observations and extrapolations say nothing about whether all these Earth-size planets will actually have the characteristics of Earth: its density, its just-right distance from the sun, the fact that it is a rocky structure rather than gaseous ball.” The article notes “additional support” for this estimate is expected from Kepler telescope results due in February. Howard said, “What this means is that, as NASA develops new techniques over the next decade to find truly Earth-size planets, it won’t have to look too far.”

BBC News" (10/29, Ghosh) notes, “This estimate is based on observations from nearby stars taken by the…twin 10-metre Keck telescopes in Hawaii. These show that 22 of the stars had detectable planets.” However, “according to Dr Robert Massey of the Royal Astronomical Society, “most of the worlds they predict exist would be too close” to the parent star “to be habitable.”

The Wired (10/29, Grossman, 743K) “Wired Science” blog reports Josh Winn of MIT, who was not part of the study, calls it a “landmark paper.” According to the article, “Unlike previous surveys, Howard and colleagues were just as interested in stars that lack planets as stars that host them. To avoid biasing the study toward planet-bearing stars, the team selected the nearest and brightest stars in the 120,000-star Hipparcos Catalog.” Furthermore, “the observations also showed a lot of planets between 5 and 30 times Earth’s mass, a range that theoretical models of planet formation predicted should be so empty it earned the name, ‘the planet desert.’” The article describes the results as a “windfall” for exoplanet searches.

However, Space.com (10/29, Choi) reports, “The new findings conflict with current models of planet formation and migration.” The team wants “to learn much more about extrasolar planets by combining the results of their study with forthcoming data from NASA’s planet-hunting Kepler spacecraft. While their study can detect planetary masses, Kepler can measure planet size with exquisite sensitivity.”